This issue is still current; I just wanted to add that SIMH has also published bug fixes for 3.9-0 on their website: http://simh.trailing-edge.com/interim/
Supposedly, these include "important fixes for the VAX780, PDP-11, and 1401". It may be worth to include those in an update to 3.9. The most recent file on there is from 2014, however. The same goes for beta releases on GitHub. I'm unsure of the versioning policy that SIMH follows; maybe it is worth considering picking a specific git commit for the time being and stabilizing that.
